xSiteable is a complete all-you-need package for creating sites that are fully relational, open source, fully templating-enabled, using only XML-based technologies to help you create complex sites on the fly. It packs such features as topic maps, notation for content, and the fast Sablotron xslt parser.
betterFORM is an implementation of the W3C XForms 1.1 Recommendation. It allows easy creation of highly dynamic Web 2.0 user interfaces with attractive controls and layout. You can add validations, calculations, actions, and events to build complete Web applications in a declarative way.